Grommet reinforcement for canvas material



July 4 19557 A. L. TOMBARI 3,328,854

GROMMET RE'INFORCEMENT FOR CANVAS MATERIAL Filed April 26, 1965 ai 3 I INVENTOR.

ALDO L. TOMBARI BY United States Patent O 3,328,854 GROMMETREINFORCEMENT FOR CANVAS MATERIAL Aldo L. Tombari, Statesville, N.C.,assigner to The Hettrick Manufacturing Company, Statesville, N C., acorporation of Delaware Filed Apr. 26, 1965, Ser. No. 450,767 1 Claim.(Cl. 24-141) This invention relates to the mounting of grommets, as usedin waterproofed canvas products, such as tarpaulins, tents, awnings andthe like.

Canvas products of the above type equipped with grommets have haddifficulty in preventing the grommets from pulling through or tearingthe material when subjected to severe stresses imposed thereon by ropespassing therethrough. Reinforcements heretofore provided for coping withthis problem have not been entirely satisfactory principally becausethey failed to hold the material positively to the grommet and becauseof inadequate support for the material where the stresses are thegreatest.

An object of this invention is to reinforce the grommet area in canvasproducts of the above character so that the reinforcing elements,grommets and canvas material are so interconnected that they cooperatein a new and improved manner more effectively to militate againsttearing and damage to the assembly and resist stresses of greatmagnitude.

Other objects and advantages of the invention will hereinafter appearand, for purposes of illustration but not of limitation, an embodimentof the invention is shown on the -accompanying drawings, in which FIGURE1 is a top fragmentary perspective view of a sheet of canvas materialprovided with grommets;

FIGURE 2 is an enlarged fragmentary plan view of an edge portion of thesheet of canvas material showing one of the grommets and the reinforcingstrip for same;

FIGURE 3 is Ia sectional view substantially on the line 3 3 of FIGURE 2;and

FIGURE 4 is an enlarged exploded view showing in perspective the twoparts of the grommet.

The illustrated embodiment of the invention shows a sheet of canvasmaterial 10, which may be waterproofed canvas for use as tarpaulins,tents, awnings and the like. The edge portions of the canvas materialare doubled upon itself to form a two ply thickness and these portionsare secured by sewed seams 12. At the corners and along the side edgeportions is a series of grommets G, which are secured and reinforced ina manner hereinafter described.

Disposed within the doubled edge portions in the region of the grommetsare flat reinforcing pieces or strips 14, which, as shown, arerectangular in configuration but may be of any desired shape, such astriangular. As will more fully appear hereinafter, each of thereinforcing strips 14 extends a considerable distance on each side ofthe grommet. For example, the strip may extend beyond the grommet -adistance of the order of the space from the center of the grommet to itsperiphery. Although the particular distance is not critical, it must beadequate to afford a reinforcement not only for the immediate area ofthe grommet but also for the adjoining area. If desired, the sewed seamspass through the reinforcing material 14 or, as in the corner portions,the two seams may extend through the reinforcing strip. The strip 14 ispreferably of a somewhat stiff material having a certain amount offlexibility, such for example as vinyl plastic or polyethylene.

In practice, the reinforcing strips are placed in the desired area andthereafter a hole 13 is punched through both the canvas material (twothicknesses) and the reinforcing strip 14. After the hole is punchedthrough the several plies, as indicated, yone of the two grommet partsmay be applied, this being the part having a sheet metal ring 15 with acircular row of teeth 16 extending at right angles from the edge of thehole in the ring. It should be understood that the hole 13 is of lessdiameter than the diameter of the circular row of teeth 16 so that whenthe ring 15 is applied, the teeth are forced through both thicknesses ofthe canvass material and also through the reinforcing strip 14 in aregion spaced from the edge of the hole.

The other grommet part has a sheet metal ring 17 and an integraloutwardly extending sleeve 18 'of a size to extend through the hole inthe ring 15. The sleeve 1S is then forcibly inserted through theregistering holes in the canvas plies and the reinforcing strip 14 andthe hole in the ring 15. Then by a suitable tool, such as is well knownfor this purpose, the lfree edge of the sleeve 18 is rolled or crimped'over against the outer face of the ring 15 and the teeth 16 bent overor clinched inwardly against the adjacent ply of canvas material.

From the above description it will be manifest that an exceedinglysecure connection is afforded between the grommet, the reinforcing stripand the canvas material so that it militates satisfactorily against theforce exerted by a rope, for example, threaded through the grommet whichwould otherwise be of suicient magnitude to tear the grommet from thematerial. Another advantage of the above construction where the grommetis disposed at a corner of the material is to prevent dog-earringthereto as is typical in such locations. An important feature of theinvention is the embedding of the teeth not only in the canvas materialbut also in the reinforcing strip in a region away from the hole therebyto distri-bute the stress exerted against the grommet over the adjacentareas of the canvas material remote from the hole through same. v

Numerous changes in details of construction, arrangement and choice ofmaterials may be effected without departing from the spirit of theinvention, especially as defined in the appended claim.

What I claim is:

A device of the class described comprising a sheet of canvas materialthe edge portions of which are doubled upon themselves to provide apocket of two ply thickness, a flat relatively stiff plastic strip ofreinforcing material in said pocket for each grommet intended therefor,each grommet consisting of a ring having a circular row of teeth on theinner side and a second ring having an integral central sleeve, theteeth of said rst ring extending through both thicknesses of canvasmaterial and said reinforcing strip, there being a h'ole punched throughboth thicknesses of canvas material and the reinforcing strip in suchmanner that the edge of the hole is spaced laterally from said teeth,the slee've of said second ring extending through said hole with thefree end crimped over against the outer face of said first ring and theteeth of said first ring being clinched against the adjacent canvasmaterial, whereby appreciable portions of said plastic strip ands canvasmaterials lie between said clinched teeth and said sleeve so thatstresses imposed on the grommet are distributed over adjcent areas ofthe canvas mate- 2,562,005 7/1951 Wenzel et al 24-141 X rial remote fromthe hole. 2,795,830 6/ 1957 Leatherman 24-141 References Cited 14 524PTNTS UNITED STATES PATENTS 5 rea Y n am' 84,900 12/1868 Norcross 24-141WILLIAM FELDMAN, Pf'ilal'y Examiner'.

629,754 7/1899 POpham 24-141 DONALD A. GRIFFIN, Examiner.

